My one slide for next week is about Heijunka. I will like to show you the importance about this basic pillar of the lean manufacturing philosophy. Some would say that the Lean Manufacturing Philosophy can be defined as The Toyota House, or the TPS House (See the image below, I did it because there were many examples on the web, please correct me if any mistake), however, it doesn’t matter how you called it, the thing is that “A house divided cannot stand”, that means that every part of the house has a role and a specific propose. In this post I will try to explain the Heijunka block as a part of the house. (Abilla, 2012)
Heijunka is a Japanese technique that in english means «Leveling» or «Production smoothing». In the application of Heijunka, production doesn´t vary according to customer demand, but relies on it to adjust the volumes and sequences of the products to be manufactured, furthermore, the production department should be sure that the components are sequenced to be available in the right quantity and at the right time (McManus, 2013). If a company implement property the Heijunca, it will helps to avoid batching, reduce wastes and finished goods inventories, reduce capital cost and production lead time, and of course eliminates unevenness in workload (MURA) and intensive work (MURI) that can lead to security problems and quality.
I have found some tools and calculations that are useful for the implementation of Heijunca in a right way:
1. Calculate tack time: (seg /min /hr)
Tack Time = Production time available / total number required
2. Calculate pitch of each product: (high volume = 12 and 30 min)
Number of pieces per unit time, based on tack time required to perform operations units.
Tack time Pitch X = Number of units in the package.
3. Establish the production rate:
Taking the lowest value of the pitch and distribute in even increments according to the product to be manufactured, and the actual total daily production time.
4. Creating Heijunka box:
Used to manage leveling the volume and variety of production over a specific period of time physical device
Here is an strange video, that explain in a funny way what Heijunka is.